Single-leg vertical jump test as a functional test after anterior cruciate ligament reconstruction

Background: The aim of this study was to identify the correlations between the single-leg vertical jump (SLVJ) test and subjective and objective tests which were used widely for determining return-to-sports (RTS) after anterior cruciate ligament reconstruction (ACLR). Methods: Seventy-five patients (29.5 +/- 9.2 years) who underwent ACLR between May 2012 and Jan 2014 were included. Subjective knee scoring systems including subjective International Knee Documentation Committee (IKDC) score, Lysholm score, Tegner activity scale, and ACL-Return to Sports after Injury (ACL-RSI) scale were assessed. Objective tests were also performed. Results: The limb symmetry index (LSI) for SLVJ test and single-leg hop for distance (SLHD) test was 89.4 +/- 14.9% and 90.7 +/- 11.7%. LSI for SLVJ test was correlated to subjective IKDC scores (r = 0.26, P = 0.024), Tegner activity scale (r = 0.64, P < 0.001), ACL-RSI scale (r = 0.61, P< 0.001), LSI for SLHD (r = 0.45, P< 0.001), Co-contraction (r = 0.57, P< 0.001), Shuttle run (r = 0.52, P < 0.001), and Carioca (r = 0.54, P< 0.001) tests. In isokinetic strength tests, extensor peak torque (r = 0.30, P = 0.009) and extensor strength deficit (r = 0.41, P < 0.001) were correlated with LSI for SLVJ test. Conclusion: There were considerable correlations between SLVJ test and subjective IKDC scores, Tegner activity scale, ACL-RSI scale, isokinetic extensor muscle strength, and all other functional tests. SLVJ test could be used conveniently to determine RTS after ACLR in outpatient clinics. Level of evidence: Level IV, case series. (C) 2018 Published by Elsevier B.V.